Does soil PH affect water PH?

I just received my water PH tester. It is an Apera PH20. I calibrated it and tested my water. It is reading 7.6. The soil I am using which is Lowes Harvest Organics says it has a PH of 6.0. My question is this, If I use 7.6 PH water in 6.0 PH soil will they combine to make a PH of around 6.8? Does this make any sense? I know that the PH should be around 6 to 7 for the plant to take up all the nutrients.

Depends on the total dissolved solids (tds) in the water and any ph buffers in the soil. The lesser the solids the lesser of an effect it will have on the soil. Also if the soil has ph buffers, it can be a real bitch trying to adjust the soil ph.


Not necessarily. In a more cannabis friendly soil you would run higher pHed water than normal until your runoff gets to 6.3 to 6.8. Your soil has time released nutes, which will submarine your pH every time you water regardless of the pH of the water you are putting in, so it is going to be hard to manage. I would check your runoff pH and go from there. Better yet, if transplanting is an option I would put your plant(s) in a soil buffered for cannabis such as a Fox Farm product or Roots Organics.


So if I put the test probe in the dish under the pot after watering that would tell me if this soil and water PH combination is off and by how much?

The Harvest Organics soil has me wondering. The label actually reads “slow release nutrients”. I suppose slow release and time release is essentially the same thing. The soil is very dark and rich looking and it doesn’t have anything in it that looks like a time release pellet. Usually you can see them as they look like little colored bb’s. I sifted it through my hands pretty good and picked out anything I didn’t like the look of.

I appreciate all the answers I get to my questions and my old brain is soaking up all this information. Since this is my first grow I’m sure there will be mistakes and room for improvement with the second time around. I think I’m going to give this soil a try for this grow and see what happens.

Should I buy some PH down and try to get my water down to 6.0 to 6.5? I would think it would be better than using 7.6 water.

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Test your runoff with your pH probe.

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I recalibrated my PH tester again since I wasn’t confident I did it right the first time. I have had a watering can full of water from my Brita pitcher sitting on the counter for a few days now. The PH is now testing 6.8. I wonder if the PH changes as the water sits for a period of time.

I think I am going to mock up another clay pot with the same soil and use that to test the runoff. I don’t want to drown my plant trying to get enough water in the saucer to put the probe in to test the runoff.

When you purchase Buy ph up and pH Down. You will need both eventually. When you add your nutes To your water It will drive your pH Down. you will need ph up to get back to the Sweet Spot. 6.2 to 6.5